Rack for a toy building set



FIG. 1 is a top perspective view of the rack for a toy building set showing our new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a front elevational view thereof, the rear side being identical;

FIG. 4 is a left side elevational view thereof, the right side being identical;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a top plan view thereof. 

The ornamental design for a rack for a toy building set, as shown and described. 